Telecommunications apparatuses and methods

ABSTRACT

Methods and apparatuses for activating a vehicular-capable terminal to connect to a base station and/or road side unit. Accordingly a vehicular-capable terminal which would otherwise be in idle mode can then participate in vehicular communications, if appropriate.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S.application Ser. No. 15/768,604 filed on Apr. 16, 2018, which is basedon PCT filing PCT/EP2016/072504 filed on Sep. 22, 2016, which claimspriority to EP 15194392.5 filed on Nov. 12, 2015, the entire contents ofeach are incorporated herein by reference

FIELD

The present disclosure relates to telecommunications apparatuses andmethods.

BACKGROUND

The “background” description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description which may nototherwise qualify as prior art at the time of filing, are neitherexpressly or impliedly admitted as prior art against the presentinvention.

Mobile telecommunications systems, such as those based on the 3GPPdefined UMTS and Long Term Evolution (LTE) and Long Term EvolutionAdvanced (LTE-A) architecture, are able to support more sophisticatedservices than simple voice and messaging services offered by previousgenerations of mobile telecommunications systems. For example, with theimproved radio interface and enhanced data rates provided by LTEsystems, a user is able to enjoy high data rate applications such asvideo streaming and video conferencing on mobile communications devicesthat would previously only have been available via a fixed line dataconnection.

The demand to deploy fourth generation networks is therefore strong andthe coverage area of these networks, i.e. geographic locations whereaccess to the networks is possible, is expected to increase rapidly.However, although the coverage and capacity of fourth generationnetworks is expected to significantly exceed those of previousgenerations of communications networks, there are still limitations onnetwork capacity and the geographical areas that can be served by suchnetworks. These limitations may, for example, be particularly relevantin situations in which there is a desire for a group of terminal devices(communications devices) to exchange information with each other in afast and reliable manner. In order to help address these limitationsthere have been proposed approaches in which terminal devices within awireless telecommunications system may be configured to communicate datadirectly with one another without some or all their communicationspassing through an infrastructure equipment element, such as a basestation. Such communications are commonly referred to generally as adevice-to-device (D2D) communications. Many device-to-devicecommunications may be transmitted by one device to a plurality of otherdevices in a broadcast like manner and so in that sense the phrase“device-to-device communications” also covers “device-to-devicescommunications”.

Thus, D2D communications allow communications devices that are insufficiently close proximity to directly communicate with each other,both when within the coverage area of a network and when outside anetwork's coverage area (e.g. due to geographic restrictions on anetwork's extent or because the network has failed or is in effectunavailable to a terminal device because the network is overloaded). D2Dcommunications can allow user data to be more efficiently and quicklycommunicated between communications devices by obviating the need foruser data to be relayed by a network entity such as a base station. D2Dcommunications also allow communications devices to communicate with oneanother even when one or both devices may not be within the reliablecoverage area of a network. The ability for communications devices tooperate both inside and outside of coverage areas makes wirelesstelecommunications systems that incorporate D2D capabilities well suitedto applications such as public protection/safety and disaster relief(PPDR), for example. PPDR related communications may benefit from a highdegree of robustness whereby devices can continue to communicate withone another in congested networks and when outside a coverage area. 3GPPhas developed some proposals for such public safety D2D use in LTEnetworks in Release12.

The automotive industry has been working for several years on solutionsto enable communication with and between vehicles, e.g. to help improvetraffic flow and safety. These techniques can range from automatictolling technologies to collision prevention mechanisms, and aregenerally known as Intelligent Transport Systems (ITS). Currently, themain radio technology under consideration in standards projects relatingto ITS is a WLAN derivative 802.11p, which would be used forbroadcasting ITS information by vehicles or road side infrastructure toother vehicles. This constitutes so-called Dedicated Short RangeCommunication (DSRC) system that is deployed at 5.9 GHz ITS band inEurope and North America (there may be different ITS bands in use inother regions, e.g. 700 MHz in Japan).

The effective range of DSRC systems is a few hundred meters and theservices are broadcast oriented (emergency vehicle notices, forexample).

However, there have also been proposals for communications based onthose used in mobile telecommunications systems, such as Long TermEvolution (LTE) based networks operating on International MobileTelecommunications (IMT) bands, to help support ITS applications, forexample to provide more capacity and potentially provide for wider andcheaper coverage. In particular, where the existing cellular networkalready covers roadways the capital expenditure costs associated withusing cellular mobile telecommunications techniques for ITS applicationsmay be significantly less than what would be needed for setting up a newDSRC-based ITS network.

Accordingly, an Intelligent Transport System may rely on D2Dcommunications of the kind proposed for mobile wirelesstelecommunications systems to allow vehicles to communicate with oneanother and with other terminal devices or network infrastructureequipment, such as a base station or specific road side infrastructure.In this regard, communications associated with connected vehicle systemsmay be conveniently referred to as V2X (vehicle-to-everything)communications, which may comprise V2V (vehicle-to-vehicle), V2P(vehicle-to-pedestrian) and V2I (vehicle-to-infrastructure). The V2Xcommunications or terminals may also be referred to as vehicularcommunications or terminals, respectively. Infrastructure in this casemay be a roadside ITS related infrastructure element, which may bereferred to as a road side unit (RSU), or a conventional Internet ormobile network infrastructure element. Some examples or services inconnected a vehicle context are Cooperative Awareness Message (CAM) andDecentralised Environmental Notification (DEN). These constituteapplications such as allowing emergency vehicles to broadcast theirpresence and allowing roadside infrastructure to broadcast speed limitinformation to vehicles.

While most of the developments in the vehicular communications fieldhave been focusing on the in-vehicle or vehicle-associated devices andsystems, it is expected that future vehicular systems will in the futurealso have to address the situation of Vulnerable Road Users or VRUs. VRUare users or terminals that are V2X-compatible and that are associatedwith a vulnerable user (e.g. pedestrian, animal, bicycle, etc.). In thecase of a pedestrian, the V2X-compatible device is likely to be asmartphone or a wearable device, which have different power consumptionrequirements than a V2X device installed in a vehicle for example, andeven more so in the case of a wearable device. For at least this reason,the level of connected times cannot be expected from a VRU UE comparedto an in-vehicle VUE for example. This can present a number ofchallenging when trying to detect the presence of a VRU (e.g. to informa vehicle-associated UE and/or the VRU's UE of a potential danger) whenthe VRU is not always connected or when its presence and/or identity maynot be known to the network.

SUMMARY

According to a first aspect of an example of the present disclosure,there is provided a method of activating a vehicular-capable terminal ina mobile telecommunications system, the mobile telecommunications systemcomprising a plurality of base stations operable to communicate with thevehicular-capable terminal and wherein at least one base station of theplurality of base stations is configured to operate as a road side unitand wherein the method comprises: the vehicular-capable terminalreceiving a list of one or more base stations selected from theplurality of base stations; upon detection that the vehicular-capableterminal is within range of a first base station, the vehicular-capableterminal determining whether to activate, based on the list of basestations, a connection with the first base station; and upon determiningto activate a connection with the first base station, thevehicular-capable terminal activating the connection with the first basestation.

According to a second aspect of an example of the present disclosure,there is provided a mobile telecommunications system for activating avehicular-capable terminal, the mobile telecommunications systemcomprising: a vehicular-capable terminal, and a plurality of basestations operable to communicate with the vehicular-capable terminal andwherein at least one base station of the plurality of base stations isconfigured to operate as a road side unit, wherein the vehicular-capableterminal is configured to receive a list of one or more base stationsselected from the plurality of base stations; the vehicular-capableterminal is configured, upon detection that the vehicular-capableterminal is within range of a first base station, to determine based onthe list of base stations whether to activate a connection with thefirst base station; and the vehicular-capable terminal is configured,upon determining to activate a connection with the first base station,to activate the connection with the first base station.

According to a third aspect of an example of the present disclosure,there is provided a mobile telecommunications system for activating avehicular-capable terminal, the mobile telecommunications systemcomprising: a vehicular-capable terminal, and a plurality of basestations operable to communicate with the vehicular-capable terminal andwherein at least one base station of the plurality of base stations isconfigured to operate as a road side unit, wherein the vehicular-capableterminal and the plurality of base stations are configured to carry outtogether the above method.

According to a fourth aspect of an example of the present disclosure,there is provided a vehicular-capable terminal for use in a mobiletelecommunications system, the mobile telecommunications systemcomprising a plurality of base stations operable to communicate with thevehicular-capable terminal and wherein at least one base station of theplurality of base stations is configured to operate as a road side unit,the vehicular-capable terminal comprising a transmitter, a receiver anda controller, wherein the controller is configured to: receive, via thereceiver, a list of one or more base stations selected from theplurality of base stations; upon detection that the vehicular-capableterminal is within range of a first base station, determine based on thelist of base stations whether to activate a connection with the firstbase station; and upon determining to activate a connection with thefirst base station, activate the connection with the first base station.

According to a fifth aspect of an example of the present disclosure,there is provided a vehicular-capable terminal for use in a mobiletelecommunications system, the vehicular-capable terminal comprising atransmitter, a receiver and a controller, wherein the transmitter,receiver and controller together are configured to operate as thevehicular-capable terminal of any of the above mobile telecommunicationssystem.

According to a sixth aspect of an example of the present disclosure,there is provided circuitry for a vehicular-capable terminal for use ina mobile telecommunications system, the mobile telecommunications systemcomprising a plurality of base stations operable to communicate with thevehicular-capable terminal and wherein at least one base station of theplurality of base stations is configured to operate as a road side unit,wherein the circuitry comprises a controller element and a transceiverelement configured to operate together to: receive a list of one or morebase stations selected from the plurality of base stations; upondetection that the vehicular-capable terminal is within range of a firstbase station, determine based on the list of base stations whether toactivate a connection with the first base station; and upon determiningto activate a connection with the first base station, activate theconnection with the first base station.

According to a seventh aspect of an example of the present disclosure,there is provided a base station for use in a mobile telecommunicationssystem, the mobile telecommunications system comprising a plurality ofbase stations operable to communicate with the vehicular-capableterminal and a vehicular-capable terminal, wherein the base station isone of the plurality of base stations and is configured to operate as aroad side unit, the base station comprising a transmitter, a receiverand a controller, wherein the controller is configured to: transmit, viathe transmitter, a list of one or more base stations selected from theplurality of base stations to the vehicular-capable terminal, whereinthe list is for use by the vehicular-capable terminal to determine basedon the list of base stations whether to activate a connection with afirst base station of the plurality of base stations, upon detectionthat the vehicular-capable terminal is within range of a first basestation.

According to a eighth aspect of an example of the present disclosure,there is provided circuitry for a base station for use in a mobiletelecommunications system, the mobile telecommunications systemcomprising a plurality of base stations operable to communicate with thevehicular-capable terminal and a vehicular-capable terminal wherein thebase station is one of the plurality of base stations and wherein thecircuitry comprises a controller element and a transceiver elementconfigured to operate together to: transmit, via the transmitter, a listof one or more base stations selected from the plurality of basestations to the vehicular-capable terminal, wherein the list is for useby the vehicular-capable terminal to determine based on the list of basestations whether to activate a connection with a first base station ofthe plurality of base stations, upon detection that thevehicular-capable terminal is within range of a first base station.

According to a first aspect of a further example of the presentdisclosure, there is provided a method of activating a vehicular-capableterminal in a mobile telecommunications system, the mobiletelecommunications system comprising one or more base stations operableto communicate with the vehicular-capable terminal and one or more roadside units operable to communicate with the vehicular-capable terminal,wherein the method comprises: a first road side unit detecting thepresence of the vehicular-capable terminal; upon detection of thepresence of the vehicular-capable terminal, the first road side unitnotifying a first base station of the presence of the vehicular-capableterminal; upon notification of the presence of the vehicular-capableterminal, the first base station instructing the vehicular-capableterminal to connect to the first base station by transmitting anactivation message wherein the activation message is addressed to agroup of terminals comprising the vehicular-capable terminal; and inresponse to the activation message, the vehicular-capable terminalactivating a connection with the first base station and/or with thefirst road side unit.

According to a second aspect of a further example of the presentdisclosure, there is provided a mobile telecommunications system, themobile telecommunications system comprising: a vehicular-capableterminal, one or more base stations operable to communicate with thevehicular-capable terminal, and one or more road side units operable tocommunicate with the vehicular-capable terminal, wherein: a first roadside unit of the one or more road side units is configured to detect thepresence of the vehicular-capable terminal; the first road side unit isconfigured to, upon detection of the presence of the vehicular-capableterminal, notify a first base station of the one or more base stationsof the presence of the vehicular-capable terminal; the first basestation is configured to, upon notification of the presence of thevehicular-capable terminal, instruct the vehicular-capable terminal toconnect to the first base station by transmitting an activation messagewherein the activation message is addressed to a group of terminalscomprising the vehicular-capable terminal; and the vehicular-capableterminal is configured to, in response to the activation message,activate a connection with the first base station and/or with the firstroad side unit.

According to a third aspect of a further example of the presentdisclosure, there is provided a mobile telecommunications system, themobile telecommunications system comprising: a vehicular-capableterminal, one or more base stations operable to communicate with thevehicular-capable terminal, and one or more road side units operable tocommunicate with the vehicular-capable terminal, wherein thevehicular-capable terminal, the one or more base stations and the one ormore road side units are configured to carry out together any of themethods of the further example.

According to a fourth aspect of a further example of the presentdisclosure, there is provided a vehicular-capable terminal for use in amobile telecommunications system, the mobile telecommunications systemcomprising one or more base stations operable to communicate with thevehicular-capable terminal and one or more road side units operable tocommunicate with the vehicular-capable terminal, the vehicular-capableterminal comprising a transmitter, a receiver and a controller, whereinthe controller is configured to: advertise the presence of thevehicular-capable terminal to a first road side unit of the one or moreroad side units; receive, via the receiver, an activation message from afirst base station of the one or more base stations wherein theactivation message is addressed to a group of terminals comprising thevehicular-capable terminal and is for instruct the vehicular-capableterminal to connect to the first base station; and responsive to theactivation message, activate a connection with the first base stationand/or with the first road side unit.

According to a fifth aspect of a further example of the presentdisclosure, there is provided a vehicular-capable terminal for use in amobile telecommunications system, the vehicular-capable terminalcomprising a transmitter, a receiver and a controller, wherein thetransmitter, receiver and controller together are configured to operateas the vehicular-capable terminal of the mobile telecommunicationssystem of the further example.

According to a sixth aspect of a further example of the presentdisclosure, there is provided circuitry for a vehicular-capable terminalfor use in a mobile telecommunications system, the mobiletelecommunications system comprising one or more base stations operableto communicate with the vehicular-capable terminal and one or more roadside units operable to communicate with the vehicular-capable terminal,wherein the circuitry comprises a controller element and a transceiverelement configured to operate together to: advertise the presence of thevehicular-capable terminal to a first road side unit of the one or moreroad side units; receive, via the receiver, an activation message from afirst base station of the one or more base stations wherein theactivation message is addressed to a group of terminals comprising thevehicular-capable terminal and is for instruct the vehicular-capableterminal to connect to the first base station; and responsive to theactivation message, activate a connection with the first base stationand/or with the first road side unit.

According to a seventh aspect of a further example of the presentdisclosure, there is provided a base station for use in a mobiletelecommunications system, the mobile telecommunications systemcomprising one or more base stations operable to communicate with thevehicular-capable terminal and one or more road side units operable tocommunicate with the vehicular-capable terminal, wherein the basestation is one of the one or more of base stations, the base stationcomprising a transmitter, a receiver and a controller, wherein thecontroller is configured to: receive a notification from a first roadside unit of the one or more road side units, wherein the notificationis for reporting a presence of the vehicular-capable terminal detectedby the first road side unit; and upon notification of the presence ofthe vehicular-capable terminal, instruct the vehicular-capable terminalto connect to the first base station by transmitting an activationmessage wherein the activation message is addressed to a group ofterminals comprising the vehicular-capable terminal.

According to a eighth aspect of a further example of the presentdisclosure, there is provided a base station for use in a mobiletelecommunications system, the base station comprising a transmitter, areceiver and a controller wherein the transmitter, receiver andcontroller together are configured to operate as the first base stationof the mobile telecommunications system of the further example.

According to a ninth aspect of a further example of the presentdisclosure, there is provided circuitry for a base station for use in amobile telecommunications system, the mobile telecommunications systemcomprising one or more base stations operable to communicate with thevehicular-capable terminal and one or more road side units operable tocommunicate with the vehicular-capable terminal wherein the base stationis one of the one or more of base stations and wherein the circuitrycomprises a controller element and a transceiver element configured tooperate together to: receive a notification from a first road side unitof the one or more road side units, wherein the notification is forreporting a presence of the vehicular-capable terminal detected by thefirst road side unit; and upon notification of the presence of thevehicular-capable terminal, instruct the vehicular-capable terminal toconnect to the first base station by transmitting an activation messagewherein the activation message is addressed to a group of terminalscomprising the vehicular-capable terminal.

According to a tenth aspect of a further example of the presentdisclosure, there is provided a road side unit for use in a mobiletelecommunications system, the mobile telecommunications systemcomprising a vehicular-capable terminal, one or more base stationsoperable to communicate with the vehicular-capable terminal and one ormore road side units operable to communicate with the vehicular-capableterminal, wherein the road side unit is one of the one or more road sideunits and comprises a transmitter, a receiver and a controller, whereinthe controller is configured to: detect the presence of thevehicular-capable terminal; and upon detection of the presence of thevehicular-capable terminal, notify a first base station of the one ormore base stations of the presence of the vehicular-capable terminal forthe first base station to instruct the vehicular-capable terminal toconnect to the first base station by transmitting an activation message,the activation message being addressed to a group of terminalscomprising the vehicular-capable terminal.

According to a eleventh aspect of a further example of the presentdisclosure, there is provided a road side unit for use in a mobiletelecommunications system, the road side unit comprising a transmitter,a receiver and a controller, wherein the transmitter, receiver andcontroller together are configured to operate as the first road sideunit of the mobile telecommunications system of the further example.

According to a twelfth aspect of a further example of the presentdisclosure, there is provided circuitry for a road side unit for use ina mobile telecommunications system, the mobile telecommunications systemcomprising a vehicular-capable terminal, one or more base stationsoperable to communicate with the vehicular-capable terminal and one ormore road side units operable to communicate with the vehicular-capableterminal, the road side unit being one of the one or more road sideunits, wherein the circuitry comprises a controller element and atransceiver element configured to operate together to: detect thepresence of the vehicular-capable terminal; and upon detection of thepresence of the vehicular-capable terminal, notify a first base stationof the one or more base stations of the presence of thevehicular-capable terminal for the first base station to instruct thevehicular-capable terminal to connect to the first base station bytransmitting an activation message, the activation message beingaddressed to a group of terminals comprising the vehicular-capableterminal.

According to two further aspects of the present disclosure, there isprovided computer software which, when executed by a computer, causesthe computer to perform any of the methods discussed above and a storagemedium which stores said computer software.

Further respective aspects and features are defined by the appendedclaims.

The foregoing paragraphs have been provided by way of generalintroduction, and are not intended to limit the scope of the followingclaims. The described embodiments, together with further advantages,will be best understood by reference to the following detaileddescription taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings wherein likereference numerals designate identical or corresponding parts throughoutthe several views, and wherein:

FIG. 1 provides a schematic diagram illustrating an example of a mobiletelecommunications system;

FIG. 2 schematically represents a wireless telecommunications systemaccording to certain embodiments of the disclosure;

FIG. 3 schematically represents an example of a situation potentiallydangerous for a vulnerable road user;

FIG. 4 schematically represents an example of a mobile network;

FIG. 5 schematically represents a legacy tracking area technique;

FIG. 6 schematically represents an example of a VRU terminal movingacross a network in accordance with the present disclosure;

FIG. 7 schematically represents another example of a VRU terminal movingacross a network in accordance with the present disclosure;

FIG. 8 schematically illustrates an example method of activating a V2Xterminal in a mobile telecommunications network;

FIG. 9 schematically illustrates an example sequence for activating avehicular-capable terminal;

FIG. 10 schematically illustrates another example sequence foractivating a vehicular-capable terminal;

FIG. 11 illustrates an example call flow for activating a VRU;

FIG. 12 represents an example method of activating a vehicular-capableterminal in a mobile telecommunications network; and

FIG. 13 illustrates an example terminal and an example base station.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 provides a schematic diagram illustrating some basicfunctionality of a mobile (cellular) telecommunications network/system100, in this example operating generally in accordance with LTEprinciples, and which may be adapted to implement embodiments of thedisclosure as described further below. Various elements of FIG. 1 andtheir respective modes of operation are well-known and defined in therelevant standards administered by the 3GPP® body, and also described inmany books on the subject, for example, Holma, H. and Toskala, A. [1].It will be appreciated that operational aspects of thetelecommunications network which are not specifically described belowmay be implemented in accordance with any known techniques, for exampleaccording to the relevant standards and known variations thereof.Furthermore, it will be appreciated that whilst some specific examplesdescribed herein may refer to implementations based around particular3GPP implementations, the same principles can be applied regardless ofthe underlying operating principles of the network. That is to say, thesame principles can be applied for wireless telecommunications networksoperating in accordance with other standards, whether past, current oryet to be specified.

The network includes a plurality of base stations 101 connected to acore network 102. Each base station provides a coverage area 103 (i.e. acell) within which data can be communicated to and from terminal devices104. Data is transmitted from base stations 101 to terminal devices 104within their respective coverage areas 103 via a radio downlink. Data istransmitted from terminal devices 104 to the base stations 101 via aradio uplink. The uplink and downlink communications are made usingradio resources that may be used by the operator of the network 100. Thecore network 102 routes data to and from the terminal devices 104 viathe respective base stations 101 and provides functions such asauthentication, mobility management, charging and so on. In addition tothe base stations 101 and terminal devices 104, the system may furthercomprise one or more relay nodes/devices. These may be used to enhancecoverage for terminal devices operating in the relevant cell(s). Thedeployment of relay nodes (e.g. in terms of their locations) may followgenerally established techniques for using relay nodes to supportcoverage in wireless telecommunications systems. In terms ofterminology, it will be appreciated that terminal devices may also bereferred to as mobile stations, user equipment (UE), user terminal,mobile radio, terminal, device, and so forth. Similarly, base stationsmay also be referred to as transceiver stations/nodeBs/e-nodeBs/eNBs,and so forth. Furthermore, relay nodes may also be referred to as relaydevices/relays, and so forth. In some example implementations of thepresent disclosure, a terminal device may be operating as a relay nodeto assist in supporting communications associated with other terminaldevices. That is to say, the functionality of a relay device may beprovided by a suitably configured terminal device.

Mobile telecommunications systems such as those arranged in accordancewith the 3GPP defined Long Term Evolution (LTE) architecture use anorthogonal frequency division multiplex (OFDM) based interface for theradio downlink (so-called OFDMA) and the radio uplink (so-calledSC-FDMA).

FIG. 2 schematically shows a telecommunications system 200 according toan embodiment of the disclosure. In particular, FIG. 2 represents anoperating scenario in the context of an Intelligent Transport System(ITS) scheme whereby vehicles equipped with terminal devices areconfigured to support device-to-device communications(vehicle-to-vehicle communications) to allow them to communicate withone another to exchange information using the radio resources of thewireless telecommunications system 200. The telecommunications system200 in this example is based broadly on an LTE-type architecture withmodifications to support device-to-device communications (i.e. directsignalling exchange between terminal devices to communicate data betweenthem) generally in accordance with previously proposed schemes for D2Dcommunications. As such many aspects of the operation of thetelecommunications system 200 are already known and understood and notdescribed here in detail in the interest of brevity. Operational aspectsof the telecommunications system 200 which are not specificallydescribed herein may be implemented in accordance with any knowntechniques, for example according to the established LTE-standards andknown variations and modifications thereof (e.g. to provide/introducesupport for D2D communications in a vehicle-to-vehicle/ITS context).

It will be appreciated the information content of the communicationsbetween the vehicles is not significant to the principles underlying theoperations described herein. Thus in any given case the informationcontent will depend on the implementation at hand and the functionalitythe particular ITS scheme provides. For example, in some implementationsthe information exchanged through the vehicle-to-vehicle communicationsmay comprise information regarding the speed and direction of therespective vehicles and relevant operating characteristics, such aswhether the vehicle brakes are being applied and whether the vehicle isindicating an intention to turn/change direction.

The telecommunications system 200 comprises a core network part (evolvedpacket core) 202 coupled to a radio network part. The radio network partcomprises a base station (evolved-nodeB) 204, a first terminal device206 and a second terminal device 208. Each terminal device is deployedwithin a vehicle for providing vehicle-to-vehicle communicationfunctionality. It will of course be appreciated that in practice theradio network part will comprise a plurality of base stations serving alarger number of terminal devices (vehicles) across variouscommunication cells. However, only a single base station and twoterminal devices are shown in FIG. 2 in the interests of simplicity forthis Figure.

As with a conventional mobile radio network, the terminal devices 206,208 are arranged to communicate data to and from the base station(transceiver station) 204. The base station is in turn communicativelyconnected to a serving gateway, S-GW, (not shown) in the core networkpart which is arranged to perform routing and management of mobilecommunications services to the terminal devices in thetelecommunications system 200 via the base station 204. In order tomaintain mobility management and connectivity, the core network part 202also includes a mobility management entity (not shown) which manages theenhanced packet service, EPS, connections with the terminal devices 206,208 operating in the communications system based on subscriberinformation stored in a home subscriber server, HSS. Other networkcomponents in the core network (also not shown for simplicity) include apolicy charging and resource function, PCRF, and a packet data networkgateway, PDN-GW, which provides a connection from the core network part202 to an external packet data network, for example the Internet. Asnoted above, the operation of the various elements of the communicationssystem 200 shown in FIG. 2 may be broadly conventional apart from wheremodified to provide functionality in accordance with embodiments of thedisclosure as discussed herein. It will further be appreciated that forother implementations which are based around wireless telecommunicationssystems operating in accordance with different standards, the networkarchitecture may be correspondingly different.

The first and second terminal devices 206, 208 are D2D (morespecifically, V2V) enabled devices configured to operate in accordancewith embodiments of the present disclosure as described herein. Theterminal devices 206, 208 each comprise a respective transceiver unit205, 209 for transmission and reception of wireless signals and arespective controller unit 207, 211 configured to control the respectiveterminal devices 206, 208. The respective controller units 207, 211 mayeach comprise a processor unit which is suitably configured/programmedto provide the desired functionality using conventionalprogramming/configuration techniques for equipment in wirelesstelecommunications systems. The respective transceiver units 205, 209and controller units 207, 211 are schematically shown in FIG. 2 asseparate elements. However, it will be appreciated for each of theterminal devices the functionality of the terminal device's receiver andcontroller units can be provided in various different ways, for exampleusing a single suitably programmed general purpose computer, or suitablyconfigured application-specific integrated circuit(s)/circuitry. It willbe appreciated the first and second terminal devices 206, 208 will ingeneral comprise various other elements associated with their operatingfunctionality in accordance with established wireless telecommunicationstechniques (e.g. a power source, possibly a user interface, and soforth).

The base station 204 is configured to support communications with theterminal devices and may also in some situations for some examples playa role in configuring aspects of D2D communications between the terminaldevices, for example establishing which radio resources may be used forD2D communications between terminal devices operating within thecoverage area of the base station 204. The base station 204 comprises atransceiver unit 201 for transmission and reception of wireless signalsand a controller unit 203 configured to control the base station 204.The controller unit 203 may comprise a processor unit which is suitablyconfigured/programmed to provide the desired functionality usingconventional programming/configuration techniques for equipment inwireless telecommunications systems. The transceiver unit 201 and thecontroller unit 203 are schematically shown in FIG. 2 as separateelements for ease of representation. However, it will be appreciatedthat the functionality of these units can be provided in variousdifferent ways, for example using a single suitably programmed generalpurpose computer, or suitably configured application-specific integratedcircuit(s)/circuitry or using a plurality of discretecircuitry/processing elements for providing different elements of thedesired functionality. It will be appreciated the base station 204 willin general comprise various other elements associated with its operatingfunctionality. For example, the base station 204 will in generalcomprise a scheduling entity responsible for scheduling communications.The functionality of the scheduling entity may, for example, be subsumedby the controller unit 203.

Thus, the base station 204 is configured to communicate data with thefirst terminal device 206 over a first radio communication link 210 andcommunicate data with the second terminal device 208 over a second radiocommunication link 212. Both radio links may be supported within asingle radio frame structure associated with the base station 204. It isassumed here the base station 204 is configured to communicate with theterminal devices 206, 208 over the respective radio communication links210, 212 generally in accordance with the established principles ofLTE-based communications. Nevertheless, it will be appreciated that someembodiments may be implemented without the respective terminal devicesundertaking any base station communications, and in this regard theprinciples and some aspects described herein with regards tovehicle-to-vehicle communications may for some implementations beundertaken regardless of whether the respective vehicles (mobileterminals) are in coverage or out of coverage of a base station.Although the links 210, 212 have been illustrated as singlebi-directional links, they can comprise or consist of an uplink and/or adownlink as commonly known to the skilled person.

In addition to the terminal devices 206, 208 being arranged tocommunicate data to and from the base station (transceiver station) 204over the respective first and second radio communication links 210, 212,the terminal devices 206, 208 are further arranged to communicate withone another (and other terminal devices within the wirelesstelecommunications system) in a device-to-device (D2D) manner over a D2Dradio communication link 214, as schematically indicated in the Figure.A direct communication link between two devices can sometimes bereferred to a sidelink, which can be used to carry sidelink traffic suchas D2D traffic. The underlying principles of the D2D communicationssupported in the wireless telecommunications system of FIG. 2 may followany previously proposed techniques, but with modifications to supportapproaches in accordance with embodiments of the disclosure as describedherein.

While vehicular communications can already present challenges in amobile telecommunications network environment, when considering a VRU,the communications environment can be even more challenging. Aspreviously mentioned, a VRU UE is more likely to be a smartphone or evena wearable device, such that the connection and battery requirements forthe UE are entirely different from that of a device in an in-vehicleenvironment where it can for example be integrated to a car (and thus bepower through a vehicle power system) or be connected to the vehiclepower system, e.g. via a USB or cigarette lighter power connection.

As a result, it cannot reasonably be expected that a VRU UE (sometimessimply referred to as “VRU” in the interest of conciseness) will alwaysremain in connected mode with the network and it is more reasonable tostart from the assumption that a VRU UE is likely to be in idle mode. Inthis context, it can be difficult to discover a VRU, for example inorder to initiate any warning and activation processes that may beappropriate in a V2X/vehicular system. In particular, one of thechallenges faced in this situation relate to the fact that, in idlemode, a VRU UE may not receive or observe the V2X messages being sent inits vicinity.

More specifically, when in idle mode in current mobile networkenvironment, the terminal would generally be expected to be in aRRC_Idle mode, where the terminal camps under a cell which it hasmeasured to have the best downlink signal strength. The terminal canread paging channel periodically, wherein the paging intervals for theterminal are defined based on its IMSI. Otherwise the device goes intoDRX mode between the paging intervals. Generally in mobile networks, theserving eNB is unable to reach the device unless it is being paged bythe core network (which require prior knowledge of the IMSI of thedevice that it is paging), or unless the device chooses to establish RRCconnection (for example to initiate a call and/or data transmission).Consequently, under the existing mobile network (e.g. LTE) protocols, itis very difficult to activate a VRU in a timely fashion when it is inidle mode but near an area where it should engage in V2X communications.

FIG. 3 schematically represents an example of a situation potentiallydangerous for a vulnerable road user. In this example, a pedestrian anda vehicle are both approaching a junction and this could present adanger to the vehicle and pedestrian, with the pedestrian being most atrisk. For example, when there are no traffic lights and/or when there islimited visibility and the pedestrian is intending to cross the roadusing the zebra crossing, in order to protect VRU (the pedestrian) thesystem would ideally discover that a VRU is near the zebra crossing andalerts vehicles approaching that there is a VRU present. At the sametime, the system could also alert the VRU that a vehicle is approaching(also possibly inform the VRU on the direction from where the vehicle isapproaching). When a road side unit (RSU) is in such an area, it can beused to communicate this danger to the VRU and/or vehicle once thepotentially dangerous situation has been detected using vehicularcommunications.

As the skilled person will understand, it may not be useful to alert theVRU and vehicles where the VRU is far from any point of crossing. As aresult, the system can be more efficient when the discovery can takeplace at a close proximity to the relevant danger area. Likewise,warning each and every VRUs in the range of a RSU through paging channelcan also be very inefficient. In other words, for the system'sefficiency to improve, it may be desired to have warnings which aregeographically and timely relevant. Ideally, the RSU would detect theVRU device only when it is in the proximity of the point of crossing orof danger, after which the device is alerted to switch on its V2Xcommunication functionality so that it can participate in the warningsystem (as a transmitter and/or receiver of warning information). Forexample, the VRU device may be alerted via the V2X communicationinterface and/or via the eNB in downlink. The challenge in alerting theVRU device is that it may be in idle mode. When the UE is in idle mode,it can generally only be accessed by paging messages from the eNB, whichintroduces the difficulty of identifying the relevant devices to contactthrough the paging messages. In particular, in view of the vehicularenvironment, this situation is different from that of an arriving phonecall, where the device can be paged by its IMSI which is known beforethe terminal is to be paged. In this case, the identity of the device tocontact is effectively unknown to the network as far as its IMSI isconcerned such that sending a paging message directed to a specific VRUthat is approaching a RSU and/or a high risk area cannot be done usingconventional means.

In view of the challenges presented above in respect of vehicularcommunications and of VRUs, the safety and efficiency of vehicularsystems (and in particular of warning vehicular systems) could benefitfrom being able to efficiently and reliably detect the presence of a VRUin the proximity of a dangerous area and alert the VRU (in particular ifthe device is in idle mode as this may involve the device switching to aconnected mode).

In a first example of one or more techniques of the present disclosure,a vehicular-capable terminal is provided with a list of base stations(that also operate as RSU) and the terminal is configured toautomatically change to connected mode when within range of one of thesebase stations. Accordingly, the terminal will be able to detect thepresence of a RSU which may require the VRU UE to participate in awarning system.

FIG. 4 schematically represents an example of a mobile network inaccordance with the present disclosure. In this example, the networkcomprises a base station eNB1 operating as a conventional base stationwhile four base stations RSU 1-4 also operate as RSUs. Avehicular-capable terminal, in this case a VRU UE, is also part of thenetwork and is sent a list of RSU for determining which RSU to connectto. In the example of FIG. 4 , the terminal is informed of the RSUs itshould not connect to. For example, once connected to RSU1, VTAC1 can beadded to the list communicated to the terminal to avoid a ping pongeffect. However, in other examples, the list may indicate which RSU theterminal should connect to. In either case, the terminal can thendetermine whether to automatically connect to a RSU based on the list ofRSUs, thereby automatically activating a terminal that was otherwise(and would have otherwise remained) in idle mode. In the presentdisclosure, the list of base stations/RSUs may also be referred to theVTA list where VTA stands for Vehicular Tracking Area and, likewise, thebase stations in the list may be identified using a Vehicular TrackingArea Code (VTAC). In some examples, the VTAC may for example be the cellID for the base station. In the example of FIG. 4 , the cells for theRSU are generally smaller than that of the non-RSU eNB. Although this isnot necessary and the cells could each be of any size, as appropriate,it is generally expected that the RSU will handle vehicularcommunications in a relatively limited area such that, in practice, theRSU cells are likely to be smaller than the non-RSU cells. Generally,the RSUs are expected to send a certain number of vehicularcommunications by broadcast such that, if the RSU cell is too large, thevehicular notifications may reach non-relevant devices (e.g. devices ina different road where no notification is required) and may thus resultin unnecessarily notifying some terminals (thereby wasting wirelessresources and power at both the RSU's and device's sides). This factoris one of the reasons why a RSU cell is expected to be smaller and,potentially, to operate as a small cell within coverage of base station.However in other examples the RSU cell may be larger and/or there maynot be any overlay base station cell within which the RSU cell operatesas a small cell and the example of FIG. 4 is for illustrative purposesonly.

With a view to addressing the limitations discussed above regarding thediscovery and activation of idle mode VRUs in V2X networks, each RSU/eNBof FIG. 4 would thus have a cell ID wherein UEs roaming in the areawould be aware of which RSUs it should automatically connect to or itshould not connect to. Also, with a view to minimising changes to thelegacy system and idle mode, in some examples, the techniques of thefirst example can be implemented re-using the legacy Tracking Area “TA”techniques already available in the mobile networks. In order toillustrate the TA arrangements commonly found in mobile networks, FIG. 5schematically represents a legacy tracking area technique. A device inidle mode generally does not connect to the network during idle modemobility (e.g. from one base station to another) unless it performs a TAupdate. Tracking Areas are groups of base stations that constitute units(TAs) which the MME uses when paging UEs. In practice, the terminalupdates the network only when it changes TA, not merely when it changesbase station such that the network (and in particular the MME in thecore network) only knows a UE's location on a Tracking Area level. If aterminal needs to be paged (for example because of an incoming call),the MME will request all of the base stations of the last known trackingarea of the terminal to page the device. When the idle mode UE movesacross a TA list border (which is identified using a list of TAs), thatis when it hands over to a base station from another TA, it will thenconnects to the network (to the base station and to the EMM) andperforms a TA update. During this update, the EMM will be aware of thenew tracking area for this terminal and the terminal will be given a newTA list of Tracking Areas, which generally includes the TA that the UEjust left (with a view to avoiding a ping-pong effect in TA updates).That is because, at present, TA lists include TAs that the terminalshould not automatically connect to. Generally there is a balance to befound between the size of a Tracking Area (number of base stations perTA) and paging efficiency. With a smaller tracking area, it is easierfor the MME to find where an idle mode UE is camping at and the amountof paging signalling can thus be reduced (as fewer base stations have tosend the paging message for the terminal). On the other hand, with alarger TA, the UEs will have to perform fewer tracking area updates andthus reduce the amount of tracking updates signalling. Operators forexample avoid having tracking area borders on busy roads or rail lineswith a view to reducing the chances of having large amounts and/orbursts of TA updates when a large number of devices regularly cross theTA border of when large groups of devices cross the TA border at aboutthe same time.

Returning to a case where the teachings of the present disclosure are tobe applied to a legacy environment, the existing TA arrangements can bere-used to integrate the list of RSU for the terminal to connect to. Itis noteworthy that the list of RSU, in its nature and its use, does notcorrespond to a TA list. First, the TA list identifies groups of basestations wherein, when a terminal moves from a first base station toanother base station, it either stays within the same TA or it changesto another TA but it cannot find itself connected to a base station thatis not part of a TA. In other words, the TAs represent contiguous areasof mobile coverage (with possible overlaps at the TAs' borders). On theother hand the RSU that could be included in the VTA list may not becontiguous ones and a terminal may find itself in an location where itis connected to a base station and/or a RSU but is however not withincoverage of any of the RSUs (base stations) that could be listed in aVTA list (whether the VTA list is a positive definition of RSUs toconnect to or a negative definition of RSUs not to connect to).Additionally, a tracking area includes a plurality of base stationswhereas each element in the VTA list generally relates to one basestation only. Also, the TA updates are used for the terminal to updatethe MME when it changes TA so that the MME knows where to page aterminal, whereas the VTA are not for use for paging a terminal suchthat the MME does not have to even be made aware or be updated on of thelocalisation of the terminal when it connects to eNB-based RSU.Moreover, as will be further discussed below, the type of connection setup between the terminal and/or the radio access network parts of thenetwork once the terminal enters within coverage a listed RSU can alsodiffer as the vehicular-enabled terminal may only connect to the basestation/RSU and not to the MME or to another element in the corenetwork.

Despite these differences between the TAs and VTAs, in an example of thepresent disclosure, it can be made use of the transmission of the listof TAC to a terminal, to include information on the list of RSUs at thesame time. This could also reduce the changes to the terminal as theterminal could use both the list of track areas and the list of RSUs(vehicular tracking areas) to determine when to transition out of theidle mode to the connected mode. Accordingly for vehicular-capableterminals can be managed at the same time as non-vehicular capableterminals for tracking areas updates and separately for vehicularcommunications and in particular for connection to RSU for vehicularcommunications. Accordingly non-vehicular-capable devices would only usethe TA list while the vehicular-capable devices would use the TA and VTAlist when dealing with idle mode mobility. Accordingly, the legacy idlemode mobility can still be used in this example. As the skilled personwill understand, while this implementation can reduce the changes to thelegacy system, both from a network's perspective (for communicating thelist to the terminals) and from a terminal's perspective (fordetermining when to leave the idle mode), in other examples a differentmethod may be implemented for communicating the list of base stations tothe terminals and for the terminals to know when to connect to a basestation automatically based on the list. For example, the list may besent separately to a vehicular-capable terminal any time (or sometimes,when) it connects to a base station and/or the process for the terminalto determine when to connect to a base station/RSU may be carried out bythe terminal separately from the process to determine when to connect tothe network when entering a new tracking area.

In cases where the TA update procedures otherwise available for updatingthe tracking area of a terminal are re-used for sending the list ofeNB-based RSU and for the terminal to automatically connect to thelisted RSUs, while the tracking area lists and tracking area codes forTA update and for vehicular communications would be separate, VTA codescould be provided in a manner similar to that for TA codes. In currentLTE systems a TA is identified with a Tracking Area Identity (TAI) whichis defined in TS 23.003 [2] as follows:

-   -   The Tracking Area Identity (TAI) consists of a Mobile Country        Code (MCC), Mobile Network. The TAI is composed of the following        elements:        -   Mobile Country Code (MCC) identifies the country in which            the PLMN is located. The value of the MCC is the same as the            three digit MCC contained in the IMSI;        -   Mobile Network Code (MNC) is a code identifying the PLMN in            that country. The value of the MNC is the same as the two or            three digit MNC contained in the IMSI;        -   Tracking Area Code (TAC) is a fixed length code (of 2            octets) identifying a Tracking Area within a PLMN. This part            of the tracking area identification shall be coded using a            full hexadecimal representation. The following are reserved            hexadecimal values of the TAC:            -   0000, and            -   FFFb.

In other words, TAC is a 16-bit number which together with the MobileNetwork Code and Mobile Country Code constitutes the Tracking AreaIdentity (TAI). While some documents (e.g. U.S. Pat. No. 8,537,751 [3])discuss TA updates, they generally focus on conventional TA updatetechniques and on reducing the amount of signalling for the TA updateprocedure but are not directed to vehicular environment, let alone tothe discovery of V2X terminals that are otherwise in idle mode.

As for the purposes of the VRU discovery, the “vehicular” tracking areasmay not be continuous or contiguous and are expected to be more like hotspot areas around each of the relevant/listed RSUs. Also, as the VTA arenot used for paging, a vehicular tracking area may not have a unique TAIbecause it will not be used to reach to the terminal through paging. Asa result of this use and of this distribution of VTAs, having multipleVTAs with the same identifier may not cause problems and only a limitednumber of TAIs may be used for identifying the VTA for the selectedRSUs. In some examples, the TAI for RSUs can be constructed such that itidentifies that the TA is a VTA, for example when considering theexample of the currently used TAI, using the reserved 0000 or FFFF TACcould indicate to the terminal that the TAI relates to a VTA.Accordingly legacy terminal could ignore these TAI as reserved ones andthus process the conventional non-vehicular TA only whilevehicular-capable terminals may identify these TAI as relating to VTAand thus use the information associated with these TAI to identify thelisted VTAs in the list of TAs and VTAs it has received. As anotherexample, in a case where the list of VTAs defines which VTAs theterminal should not connect to, a TAC available in the current list ofTACs could be dedicated to VTAs, and it will always be included in a TAlist that is provided for legacy terminals. Thus, the VTA is alwaysincluded in legacy terminals' TA lists and entering an RSU coverage areawon't trigger a TA update for those terminals. In practice, limiting thesize of the VTA list to one RSU can assist with the VRU UE exiting idlemode when it comes within coverage of another RSU not listed in the UE'scurrent VTA list (see for example FIG. 4 ) when the list defines whichRSUs the terminal should not connect to. This can help with the VRUregistering with the base station (and optionally network) to becomecontactable or reachable via V2X signalling when it is in the proximityof a relevant eNB-based RSU. For example, when a pedestrian carrying aVRU device (which is in idle mode) approaches an intersection with aneNB-based RSU on it (see for example FIG. 3 ), the device can detectthat it is crossing into a new VTA (either because it is not in thecurrent list identifying which VTA not to connect to or because it is inthe current list identifying which VTA to connect to) and will establishan RRC connection with the serving base station. In this manner, thedevice can automatically become active when it is in the proximity of anappropriate RSU using the VTA list, without implementing tracking ordiscovery-like techniques to detect the position of the terminal. On theother hand, when the terminal is not under coverage of a listedeNB-based RSU, the device can remain in idle mode if need be and thussave battery by only connecting to the relevant eNB-based RSU.

FIG. 6 schematically represents an example of a VRU terminal movingacross a network comprising RSUs. In particular, it depicts the track ofVRU UE originally in idle mode. The VRU UE moves in an area which issometimes within coverage of one of RSUs 1-4 and sometimes outsidecoverage. It is pointed out that in the example network in FIGS. 4 and 6(and FIG. 7 discussed below) the RSUs are within coverage of aconventional (non-RSU) base station and of the same conventional basestation. This configuration is however entirely illustrative and inother examples some or all of the RSUs may not be within coverage of aconventional base station at all or may be within coverage of adifferent conventional base station compared to at least one of theother RSUs. Likewise the example of FIG. 6 (and FIG. 7 ) is based on alist identifying which VTA the terminal should not connect to but thesame teachings apply equally to a case where the list defines which RSUthe terminal should connect to. Returning to the VRU of FIG. 6 , it isoriginally in idle mode and when idle mode measurements detect areasonably strong signal from RSU1 (the TAC of which is not on the TAlist), the UE determines that it has entered a new VTA based on the TAlist. The UE then establishes an RRC connection to RSU1 which can enableV2X connectivity such that the VRU can communicate with this RSU and,potentially, with other V2X UEs in the vicinity. In a case the UEactually continues with Tracking Area update with the core network or ina case where RSU1 and/or eNB1 are configured to update the TA list forthe terminal (even if only the part of the TA list relating to VTAs) orto update the VTA list for the terminal (e.g. if it is providedseparately from the TA list), its TA list would be amended to have thisVTAC (VTAC1) added but no other VTACs for relevant RSUs that theterminal should connect to, if within range (in addition to the normalTA list it would be provided for legacy idle mode mobility purposes).Later on, the VRU leaves the coverage area of RSU1 and is released backinto idle mode. When the VRU moves into the coverage of RSU2, the VRU UEagain detects a new VTAC which is not in its current TA list andtransitions into connected mode just as discussed above in respect ofRSU1. Likewise, the UE can then engage in V2X/vehicular communicationswith RSU2 and potentially other V2X devices in the vicinity. Thisprocess is repeated when the VRU moves out of coverage of RSU2 (back toidle mode) and then into coverage of RSU4 (back to connected mode).

As mentioned above, when the UE enters RRC connected mode after findinga VTAC which is not in its current TA list, the TA list may or may notbe amended. If the list is not amended, it continues to have the sameVTACs in it (and potentially no VTACs in it) and the UE always exits RRCidle mode when detecting a VTAC not in the list. If the TA list can beamended (by the core network, the RSU the terminal is connected to or abase station within range) and, in some cases, it would be amended toinclude the current VTAC in order to allow the UE again to find the nextRSU VTAC as being outside the list and enforce switch into RRC connectedmode.

FIG. 7 schematically represents another example of a VRU terminal movingacross a network comprising RSUs. This second example is setup in anetwork which is similar to that of FIGS. 4 and 6 however in this caseRSU 4 remains listed in the VTA list for the terminal as it movesthrough the network. In comparison to the arrangement discussed inrespect of FIG. 6 , in this example the terminal will automaticallyenter RRC connected mode when within range of RSU1 or RSU2 but when itenters the coverage area of RSU4 it will not automatically enter RRCconnected mode as RSU4 is already listed in the current VTA list. Forexample, RSU4 may not be associated with a high-risk zone for the VRUsuch that it is not considered necessary for VRU UEs to enter RRCconnected mode as it is not expected that the VRUs or that many VRUswill need to be part of a VRU warning system when using this RSU.Accordingly a vehicular-enabled terminal may enter the cell of eNB-basedRSU and may not always automatically connect to it but will only connectto the selected ones that will be identified based on a listcommunicated to the terminal (e.g. identifying RSU to connect to or notto connect to).

In some examples, when the terminal transitions into connected mode withthe RSU, it can activate a connection to the RSU (e.g. transitioninginto an RRC_connected mode) and while in a conventional arrangement theterminal would then also connect to the core network (e.g. to the MME),the terminal may not set up any connection with the core network of themobile network and, for example, may not set up any connection with theMME or any other type of anchoring element of the core network. Whilethis type of connection would be unconventional and would go against theusual connection modes and techniques of mobile networks, in the presentsituation, it can reduce the amount of signalling and power consumptionfor the terminal at least. Also, as the localisation of the terminaldoes not have to be updated for paging purposes when the VRU connects toa listed RSU and as the terminal does not connect to the network withthe intention to exchange data via the core network (e.g. with a remoteelement such as a web server, a VPN server, etc.), the terminal isunlikely to suffer from this limited connection to the core networkportion of the mobile network. As the skilled person will understand,the network can still page the terminal if need be and the terminal canstill connects to the core network if it wish, for example if it wish toconnect to a remote element via the internet. In practice and using theterminology presently used in current networks, once the RRC connectionwith the listed RSU is established, it may be sufficient for the VRU UEto only engage in vehicular communications within the RSU coverage areaand the S1 interface bearer towards the core network can be dispensedwith.

Also, terminal that will make use of the list of RSU and/or that willreceive the list may not include all terminals. In some examples, allterminals will receive this list information (e.g. as part of a moregeneral TA list), while in other examples only selected terminals willreceive this list information. For example, only terminals that arevehicular-capable will receive the list and, optionally, only terminalsthat are vehicular capable and that are identified as being associatedwith a VRU or as being likely to be associated with a VRU (e.g. awearable wristband, a bicycle device, a device for a dog collar, etc.).This may for example be based on the assumption that non-VRU V2X devicesare likely to be always connected to the network and that VRU V2Xdevices are likely to be in idle mode most of the time. In other cases(for example if it is believe that this assumption cannot reasonably bemade), all V2X devices may connect to the listed RSUs such that both VRUand non-VRU terminals can be made aware of each other, if need be. Alsoeven in cases where a large number of terminals receive the listinformation, only the vehicular-enabled or some of the vehicular-enableddevices may make use of this information as deemed appropriate.

FIG. 8 illustrates an example method of activating a V2X terminal in amobile telecommunications network. The method starts and at S801, a V2Xterminal receives a list of base stations. For example the RSUs may havebeen selected based on the level of risks for VRUs in the area and thelist may in some cases include any relevant base station(s) that theterminal should not connect to (e.g. base stations associated with aVTAC/TAC that the terminal should not connect to) while in other casesit can include any base station(s) that the terminal can connect to(e.g. comprising a subset of some of or all of eNB-based RSUs in an areaaround the terminal). Then, at S802, upon detection that the V2Xterminal is within range of a first base station of the list, the V2Xterminal determines whether to activate a connection with the first basestation, based on the list. For example, depending on the type of listused in an implementation, the terminal may determine whether the firstbase station is not on the list or is on the list. Then, upondetermining to activate a connection with the first base station, theV2X terminal activates a connection with the first base station at S803.

Accordingly, using the teachings and techniques discussed in the presentdisclosure, the terminal can automatically connect to the relevant RSUs,which may for example be associated with a high-risk zone for VRUs,thereby saving battery while out of range of the listed RSUs and beingable to engage into vehicular communications when in proximity of a RSU.Also, as the terminal will connect to RSU that are or are not includedin a list (e.g. a Tracking Area list in some examples) it received fromthe network, the network may dynamically adapt the list depending on theinformation available, whether regarding the VRU risk level of one ormore areas (which can for example be adjusted based on a number ofincidents, a time of day, a date, a luminosity level, etc.), regardingan estimated number of terminals in an area (e.g. when a large number ofpedestrian are present, a driver may already be attentive to pedestrianbut the risk to pedestrian may be increased if a driver is not aware ofthe presence of any pedestrian) or regarding any other element orinformation which may affect the risk to the VRUs in an area and/orwhich may affect the decision to notify drivers and/or VRUs in an area.

It is noteworthy that the list of RSUs/base stations communicated to aV2X device may be communicated by any base station and/or RSU asappropriate. In some examples a first one is sent to the terminal whenit first connects to the network and it can then be updated when theterminal connects to a RSU (e.g. to a listed/not listed RSU, when thedevice wishes to engage in V2X communications, etc.) and/or to a basestation (e.g. to carry out a TA update when the base station is listedor not listed on the TA list-depending on the type of list used—when theterminal otherwise connects to the network to exchange data and/or whenit has been paged, etc.).

As mentioned above, on some examples, in a case where the mobiletelecommunications network is configured such that, when the V2X and/ornon-V2X terminal connects to the network, the vehicular-capable terminalconnects to an element in a core network portion of the mobiletelecommunications network (e.g. an anchor element of the core networksuch as an MME) but when a terminal connects a RSU because it is or isnot on the list (depending on the type of list selected) it hasreceived, for example in a Tracking Area list, then the terminalconnects to the base station/RSU but not to the element in the corenetwork. Viewed from one perspective, the terminal connects to the basestation and optionally to any other element in the radio access network(“RAN”) but does not connect to any element in the core network. Whilethe connection to the RAN may cause signalling to be sent to the corenetwork (e.g. for billing or monitoring purposes), the terminal itselfdoes not establish a connection with the core network.

Also, while in the present disclosure the examples generally discuss theidle and connected mode as being the RRC idle and connected modes, theskilled person will understand that this is based on the currentconfiguration of mobile networks and of connections between terminalsand base station but that the same principles and teachings would applyequally in a network with a different configuration and with differenttypes of connections between terminals and based stations.

Moreover, in some examples the list of eNB-based RSUs may be associatedwith timing information for the V2X terminal to connect to the listedRSUs (e.g. at night the risk for VRU may be increased such that theterminal may be instructed, via the list, to connect to these RSUs onlyat certain times of day) and/or terminal type information. For example,a V2X UE that is associated with a pedestrian may connect to differentRSUs compared to a V2X UE associated with a bicycle or an animal forexample. Accordingly the terminal type information may identify to whichtype or types of terminals one or more of the listed RSUs apply to. Insome examples, the timing and terminal type information may be usedtogether such that the effective list of RSUs that a terminal willconnect to will sometimes depend on both the time and the terminal type(e.g. timing information may apply to a first type of terminals but notto a second type of terminals).

In other examples, with a view to communicating with VRU UEs, the VRUUEs can notify RSU of their presence, for example using low-powertechnologies such as Bluetooth (“BT”), LC-MTC (Low Complexity-MachineType Communications) or other radio interfaces and technologies may beconsidered for the discovery purpose. For example, the VRU may announceits presence using a BT beacon sent on a regular basis for discoverypurposes or using any other type of technology and techniques for theterminal to announce its presence. Accordingly, a RSU may intercept thisdiscovery/presence message and may thus become aware of the presence ofthe terminal in its proximity. However, while the presence of a VRU UEmay be known to the RSU and thus potentially to the network, theidentity of the VRU UE that has announced its presence is unlikely to beknown. As a result, if the terminal is to be warned by the network forvehicular warning purposes, the network does not know how to contact theVRU that has announced its presence. As previously mentioned, VRU UEsare unlikely to be regularly or continuously connected to the networkand are expected to be in idle mode most of the time such that, when inidle mode, the network does not know which UE to contact for V2Xwarnings.

In a second example of one or more techniques of the present disclosure,there are provided teachings and techniques wherein a vehicular-capableterminal can be activated, after it has announced its presence, bysending an activation message instructing the vehicular-capable terminalto connect to a base station wherein the activation message is sent to agroup of terminals comprising the vehicular-capable terminal. Inaccordance with the teachings of the present disclosure and of thissecond example, there is therefore provided a method for detecting thepresence of a VRU in a V2X environment such that the V2X enabledvehicles (or any relevant type of V2X device) may be warned about thepresence VRU if appropriate.

FIG. 9 illustrates an example sequence for activating avehicular-capable terminal. In this example, the VRU UE first notifiesits presence to a detector or sensor associated with a RSU. It isnoteworthy that a RSU may be associated with one or with more than onesensor (it is for example associated with two sensors in the example ofFIG. 9 ). Then, at the second stage, the VRU UE is activated inaccordance with the teachings of the present invention. This activationresults in the terminal connecting to a selected base station (stage 3)and then at stage 4, the VRU can engage in vehicular communications.While the techniques to be used for stage 1 of the procedure are outsidethe scope of the present disclosure, the techniques presented hereinfacilitate stages 2-4 of this procedure, in particular stage 2 of theprocedure.

In a first implementation, illustrated with reference to FIG. 10 , theterminal is activated using a paging message from the base station oncethe presence of the VRU is detected near a sensor. In some examples, thepaging message could be sent as a conventional message to all terminalsin the paging area covering the sensor. However, this would result inall of the terminals in the relevant paging area for the sensor/RSU/eNBbeing asked to connect to the network at the same time when only oneterminal is intended to connect. As a result a significant amount ofwireless and power resources will be used unnecessarily and, in view ofthe important waste of paging and uplink RACH resources, this solutionis unlikely to be adopted by network operators in practice.

In some examples, a dedicated V2X and/or VRU IMSI may be used withexisting paging processes. This could assist in identifying which UEswill activate in response to the paging message. Conventionally, a UEhas a unique IMSI (from its SIM card), which determines at which pagingoccasions it reads the paging channel. The UE is paged by the corenetwork based on a combination of its IMSI and core networkidentification for the UE. However, as previously discussed, a VRUdevice that has been detected in an area may not be known to the corenetwork by its identifier such that it then cannot be paged by the corenetwork using its IMSI. However, once the eNB knows that there are oneor more VRU devices that need to be activated, it could send/request apaging message to be sent to that particular dedicated IMSI that thevehicular-capable and/or VRU UEs can receive and respond to.Additionally and optionally, the use of the V2X IMSI could mean for theterminals that, by default, they have to get V2X connected, but notnecessarily RRC Connected or connected to the core network, unless theyhave been paged conventionally and/or unless they wish to establish aconnection with the base station and/or core network for any otherreasons.

In other examples, a specific RNTI may be configured forvehicular-enabled terminals only and, optionally one may be configuredfor VRU terminals only. As for the dedicated IMSI, vehicular-enabledterminals or VRU terminals, respectively, would accordingly understandthe paging message to be directed to them and carry on with thediscovery and activation procedure while other terminals would simplynot read or ignore the paging messages with this type of specificallyallocated RNTI. While this would result in all other V2X devices or VRUsdevices—respectively—in the relevant area (e.g. the tracking area forpaging the area covering the sensor) entering a connected moderegardless of whether they are near a VRU sensor or not, in view of thecompatibility with existing mobile networks techniques and procedures,such an implementation could be considered worthwhile. In other words,while this implementation would result in a waste of resources, thewaste is reduced compared to paging all devices and the compatibility assufficient to counterbalance the waste of resources in some cases.

In other examples, rather than re-using existing paging mechanisms, thepaging of the terminal can be carried out in an even more targetedmanner with a view to reducing the number of terminals that may have toconnect to the network unnecessarily. In particular, the core network(e.g. the MME in the case of paging) may not be involved in the usualmanner. In particular, the main purpose of the paging message is toactivate the VRU device to return to active state so that it can startobserving and communicating with its surroundings for vehicularcommunications and services, which need not involve the MME or corenetwork like for an incoming call for example. With this in mind, insome examples, only a base station selected for the notified sensorand/or RSU may send a paging message to activate the terminal. As forthe case where an entire tracking area is paged, in some implementationsthis paging by a base station may be carried out using a specificRNTI/IMSI allocated to V2X and/or VRU device notification or using anyother means suitable for activating only the devices supporting VRUsand/or V2X communications. In other words, with such a basestation-based paging, the VRU device is not paged by the core networkaccording to conventional paging mechanisms, but is paged by a local eNBfor the purpose of V2X communications.

Once the device has been activated, it can then connect to the basestation (stage 3) and, optionally, to the network and, once it isconnected, it can engage in V2X communications if appropriate (stage 4)and it can for example start receiving VRU warning messages sent in itsvicinity. In cases where the terminal connects to the network followinga paging message from the base station only, then from core networkpoint of view the connection appears to be coming from the VRU deviceinitiating a call/connection as the terminal appears to request an RRCconnection and a connection to the MME (and/or any other appropriateelement of the core network) without a previous request from the corenetwork side for the terminal to connect. For example, the terminal mayalready be aware that the activation is for V2X purposes (e.g. because aV2X RNTI/IMSI was used, as discussed above) or because of a V2Xindicator in the activation message from the base station, and it maythus decide to connect to the base station only and not to connect tothe core network as it would otherwise do (e.g. if it is not aware thatthe activation is for V2X services only or if it is configured to alwaysconnect to the core network).

Also, in some examples and as discussed in respect of the first exampleabove, the terminal may only set up a connection to the RSU and/or tothe local base station without setting up a connection to the corenetwork such that it can engage in local V2X communications without corenetwork connectivity. As previously discussed, this may in some casesinvolve some signalling in the core network (e.g. for billing and/ormonitoring) but in terms of data connection the core network is notaware of the terminal being active. In other words, unless the terminalotherwise requires setting up end-to-end bearers (e.g. for datacommunication via the internet), the communication would only involveV2X connectivity to nearby other V2X devices, and thus the involvementof the MME and the S1 interface in the process may be different than ina traditional cellular call set-up.

The base station that is used for the local paging and/or for the localconnectivity in accordance with the teachings proceeded above may beselected for example based on its coverage area and its current load.For example, some localisation information may be derived from thelocation of the sensor and/or RSU that has detected the presence of theterminal and one or more base stations covering this area may beidentified. If a plurality of base station have thereby been identified,a base station may be selected based on any suitable criterion or set ofcriteria, for example based on the current load of the identified basestations. In some examples, the paging may also be performed by two ormore base stations. For example, if a sensor and/or RSU are locatedwithin coverage of two base station near the borders of each basestation, then both base station may be selected for paging the terminalas the VRU may for example only be reachable via one of the two basestation but it may not be known in advance which one is expected to bethe most likely base station covering the VRU.

FIG. 11 illustrates an example call flow for activating a VRU inaccordance with the teachings discussed above. First, at S1101 the VRUnotifies its presence and this is detected by a sensor. The sensor canthen report the presence of a VRU to the RSU (S1102). In this examplethe RSU then forwards this notification to a base station however inother examples the RSU may not forward the notification to anotherelement (for example in a case where the RSU is a eNB-based RSU suchthat it is also a base station). Then the base station having receivedthe notification of the presence of the VRU can instruct at S1103 theVRU to connect to the base station using a message sent to a group ofdevices including the VRU (as the base station is at this stage stillnot aware of the identity of the VRU UE). This can be implemented usingfor example a paging or paging-like message or using any other suitabletechniques in accordance with the present disclosure. Before, after orat the same as S1103, the RSU and/or base station can notify (S1104) anyV2X device in the area that is already known and active to the RSUand/or base station of the presence of a VRU in the area. In someexamples, based on the position of the sensor and on localisationinformation for the active V2X devices in the area (and optionally onthe type of V2X device), the notification of the presence of the VRU canbe transmitted to all of the vehicular-capable devices in the range ofthe RSU and/or base station's cell or to a selection of thesevehicular-capable devices. Accordingly, the notified V2X UE(s) can thenstart being attentive to the potential presence of a VRU (S1105). Inparallel, before or after the notification of the V2X devices, the VRUinstructed at S1103 can connect to the base station, for example totransition into the RRC_connected state (S1106), and/or connect to theRSU (S1107). As the skilled person will recognised, in view of theprevious discussion on the type of RSU, it will be understood thatwhether the terminal carried one or the other or both of S1106 and S1107may depend on the type of RSU and/or on the implementations for V2Xservices and communications. If for examples in some environments theVRU UE may be able to engage in V2X communications without beingconnected to the base station, the UE may only connect to the RSU andmay not connect to the base station. In other cases, if the terminal isexpected to always connect to a conventional base station (e.g. even incases where the RSU is an eNB-based RSU), then the terminal will carryout both S1106 and S1107. Then the VRU UE can engage in V2Xcommunications (S1108) if appropriate, for example to receive warningsregarding a possible risk associated with the presence of another V2Xdevice in the area. Optionally, once the RSU is no longer within rangeof the RSU (S1109)—which can be detected by either or both the VRU andthe RSU—the VRU can return into idle mode at S1110. In other examples,this can be carried out, if appropriate at any other suitable time, forexample once the VRU UE leaves coverage of the base station.

In other implementations, rather than using paging or paging-likemechanisms as discussed above, the activation of the VRU UE may becarried out using system information. In mobile networks, the networkregularly or periodically transmits system information to all of theterminals and this information is read by all terminals including theconnected and the idle terminals. Accordingly, this broadcasted systeminformation may be used for activating VRUs.

In current implementations, the mobile network transmits SystemInformation Blocks (SIBs) repeatedly, on intervals that can be set on anetwork-by-network basis. In accordance with the present disclosure, aSIB may be transmitted for V2X related information, for example via theintroduction of a new SIB for VRU activation. This technique can reducethe amount of changes to the network by adding a new SIB forvehicular-related services for example as new SIB 10-12 and 13 have beenintroduced recently. Accordingly, all the UEs reading the paging message(for transmitting this system information) would read the systeminformation blocks whether they are in connected mode or idle mode andUEs in idle mode could thus be reached in this manner. Additionally,using a dedicated SIB for V2X services and/or for VRU activation,location information regarding the RSU that requests VRU activation canbe included in the SIB (e.g. by appending it to the payload) and onlythe V2X enabled UEs that are in the proximity of the RSU (e.g. that candetect the RSU) may then be activated. This could further reduce thenumber of devices to become active from potentially all V2X or VRUdevices in the cell to all V2X or VRU devices close to the relevant RSU.Accordingly, only this limited number of V2X devices would be activatedand connect to the base station while the others could remain in idlemode.

As for the examples discussed above using a paging message, onceactivated the terminal may not always establish an end-to-end bearerwith the core network. In some example, this can even be configurable bythe network dynamically and on a case-by-case basis. For example, when anew system information field is added to the SIBs that the networkbroadcasts periodically, a pre-defined parameter may be used to indicatewhether the V2X or VRU UE activated would establish an end-to-endconnection when activated or whether it could remain connected to thebase station only (e.g. RRC connected mode only with the serving eNodeBthat will set up the V2X connection via the PC5 or Uu interface).

While documents can be found (e.g. US 20150002311 [4]; DE 102012211172[5]; or US 20110090093 [6]) that discuss detection of V2X devices, theyfail to address the problem of being able to reach, if possibleefficiently, a VRU device when its presence is known but its identity isnot known such that it cannot be contacted directly. Reference [4]discusses a remote locking system where, in addition to responding tothe car user's key fob, the system also detects beacons from pedestrianswith “key fobs” of their own. However this particular application canonly consider the received signal strength in considering the proximityof the VRU to the vehicle, such that the estimated position of the VRUcould be anywhere within a circle of a certain radius and, as a resultthis is subject to cause many false alarms where the VRU is in norelation of danger with respect to the vehicle receiving the beaconsignal. On the other, there is no network control over the notificationsand the network is still entirely unaware of the presence, let alone ofthe identity, of the VRU. Reference [5] discusses an arrangement where awearable device may receive notification and warning however, thisarrangement relies on the device being in connected mode and should thedevice be in idle mode, then it could not be contacted or warning by theV2X systems. Finally, reference [6] where a terminal regularly updatesthe network about its location. Again, this would result in a high powerconsumption for the terminal as the terminal would have to regularly—ifnot always—be connected to the network to send location updates (or thelast known position will be inaccurate) and this does not address theproblem of a terminal that is likely to be in idle mode most of thetime.

FIG. 12 represents an example method of activating a vehicular-capableterminal in a mobile telecommunications network in accordance with thepresent disclosure. The method starts and at S1201, a road side unitdetects the presence of the vehicular-capable terminal. The RSU maydetect the vehicular capable terminal using one or more sensors and whenat least one of the one or more sensors notifies the RSU that theterminal has been detected, the RSU can thereby detect the terminal.Then at S1202, upon detection of the presence of the vehicular-capableterminal, the road side unit notifies a base station of the presence ofthe vehicular-capable terminal. In the case that the RSU is a basestation-based RSU, then step S1202 is automatically carried out as partof S1201.

Then at S1203, upon notification of the presence of thevehicular-capable terminal, the base station instructs thevehicular-capable terminal to connect to the base station bytransmitting an activation message. The activation message is addressedto a group of terminals comprising the vehicular-capable terminal. Inresponse to the activation message, the vehicular-capable terminalactivates a connection with the first base station and/or with the firstroad side unit (S1204). In some examples the connection with the basestation can be a Radio Resources Control (RRC) connection.

Accordingly, the vehicular-capable device can be activated once itspresence is detected near a RSU. While this may involve activating otherterminals at the same time (e.g. other terminals in the group ofterminals addressed by the activation message), this still enables atleast the relevant device to become connected to the base station and/orRSU so that it can engage in V2X communications. In some examples (e.g.where the network allows it and/or where the terminal is configured toactivate in this manner), the terminal connects to the RSU only so thatit can engage in V2X communications with this RSU but does not connectto the base station upon reception of the activation message. In otherexamples the terminal may connect to both the RSU and base station, inparallel or one after the other (e.g. to the base station first and thento the RSU).

As discussed above, the activation message may be a paging message whichcan be addressed to all terminals in a tracking area comprising the basestation, to all terminals within range of the base station, to allvehicular-capable terminals within range of the base station or in thetracking area or to all VRU terminals within range of the base stationor in the tracking area. In some examples, the paging message isaddressed to all vehicular-capable terminals within range of the basestation using at least one of: a mobile subscriber identifier allocatedfor paging vehicular-capable terminals or to terminals associated withvulnerable road users; and a network temporary identifier allocated forpaging vehicular-capable terminals or to terminals associated withvulnerable road users. Accordingly the number of terminals that willpotentially receive the activation message and become connected can bereduced for a more targeted device activation.

In some examples, the activation message may be comprised in a systeminformation message transmitted by the base station.

In some examples, the base station may transmit the activation messageupon identification that the presence of the vehicular-capable terminalin the area of the road side unit is associated with a safety risk forthe vehicular-capable terminal. For example, if the base station is notaware of any other V2X terminal in the area, it may not be necessary toactivate the terminal and the terminal can remain in idle mode (in anon-connected mode) even if its presence has been detected in an areathat could be dangerous in different circumstances. Viewed from adifferent perspective, the base station can carry out a risk assessmentbefore determining whether to transmit the activation message toactivate the terminal or not. This can for example involve estimatingthe safety risk for the vehicular-capable terminal based on presenceinformation for one or more terminals other than the vehicular-capableterminal in the vicinity of the road side unit.

Once the terminal is connected (S1204), the terminal may startexchanging vehicular related data with the road side unit, ifappropriate.

As previously discussed, the terminal—when activating a connection withthe base station—may activate a connection with the base station but notwith an element in a core network portion of the mobiletelecommunications network. For example, it may not activate aconnection with an anchor element of the core network, the anchorelement being for example a MME. For example, upon activation of theconnection with the base station, the vehicular-capable terminal mayexchange vehicular related data with the road side unit while theterminal is still not connected to an element in a core network portionof the mobile telecommunications network.

Ad the skilled person will understand, the vehicular-capable terminalmay be a vulnerable road user (VRU) terminal although the teachingsdiscussed in the present disclosure (in respect of the first and secondexamples) can be equally applied to vehicular-capable devices regardlessof their VRU status.

Also, as previously mentioned, the base station may in some examples beconfigured to operate as a road side unit and, in this case the basestation and the road side unit can be the same element. It is inparticular noteworthy that this second example is applicable to botheNB-based RSUs and non-eNB-based eNB (e.g. UE-based eNB).

FIG. 13 illustrates an example terminal (1310) and an example basestation (1320) configured to communicate with each other and which mayimplement one or more techniques as discussed herein. The terminal 1310comprises a receiver 1311 and a transmitter 1312 connected to an antennafor communicating via a wireless interface. The terminal also comprisesa controller 1313 for controlling at least the receiver and transmitterof the terminal 1310. In some example, the terminal may be configuredsuch that the controller, receiver and transmitter may be configured tooperate together to operate as a D2D relay node to assist communicationfrom other terminals. Likewise, the base station 1320 comprises areceiver 1321 and a transmitter 1322 connected to an antenna forcommunicating via a wireless interface. The base station 1320 alsocomprises a controller 1323 for controlling at least the receiver andtransmitter of the base station 1320. The base station and terminal cancommunicate over the air, via the wireless interface by transmittinguplink signals from the terminal to the base station and downlinksignals from the base station to the terminal. D2D Terminals can alsocommunicate with each other directly using sidelink signals. A road sideunit in accordance with the present disclosure may also have the samestructure as the terminal and/or base station.

While FIG. 13 shows a schematic illustration of a terminal and of a basestation, it will be appreciated that while in examples of the presentdisclosure, each terminal includes a transmitter, receiver andcontroller and each base station includes a transmitter, receiver andcontroller so as to allow communication between the terminals and/orbase stations, the terminal and base station may be implemented usingany appropriate technique. For example, the controller may comprise oneor more processor units which are suitably configured/programmed toprovide the desired functionality described herein using conventionalprogramming/configuration techniques for equipment in wirelesstelecommunications systems. For each terminal, the transmitter, receiverand controller are schematically shown in FIG. 13 as separate elementsfor ease of representation. However, it will be appreciated that foreach terminal the functionality of these units can be provided invarious different ways, for example using a single suitably programmedgeneral purpose computer, or suitably configured application-specificintegrated circuit(s)/circuitry, or using a plurality of discretecircuitry/processing elements for providing different elements of thedesired functionality. It will be appreciated the terminals will ingeneral comprise various other elements associated with their operatingfunctionality in accordance with established wireless telecommunicationstechniques (e.g. a power source, possibly a user interface, and soforth).

In the examples given in the present disclosure the terminals have beenin many cases described as V2X terminals in the interest of conciseness.However, as the skilled person will recognise, the teachings of thepresent disclosure are applicable for any V2X-enabled terminals, thatis, for any terminals that have vehicle- or transportation-relatedfunctionalities activated. These can be referred to as V2X,vehicular-capable, V2X-compatible V2X enabled terminals and so forth. Insome examples the teachings of the present disclosure may be applied toall V2X terminals and in other examples they may be applied to VRU V2Xterminals only, if appropriate. Also, when reference is made to aV2X-enabled terminal, it is to be understood as a terminal with V2Xcapabilities and, optionally, as a V2X terminal with activatedV2X-functionalities. In some examples, a terminal which is configured tobe used in a V2X environment but which is not currently used in thatenvironment may not be considered as a V2X-enabled terminal in some ofthe examples above. For example the terminal may be configured to beused in association with a vehicle but may be currently used outside thevehicle as a conventional telephone such that it will not operate as V2Xterminal at this point in time and it is thus unlikely to transmit orrespond to V2X messages when the V2X-functionalities are not enabled onthe terminal.

Additionally, the method steps discussed herein may be carried out inany suitable order. For example, steps may be carried out in an orderwhich differs from an order used in the examples discussed above or froman indicative order used anywhere else for listing steps (e.g. in theclaims), whenever possible or appropriate. Thus, in some cases, somesteps may be carried out in a different order, or simultaneously or inthe same order. For example, in the call flow of FIG. 11 , S1104/S1105and S1106/S1107 may be carried out in any suitable order, such as oneafter the other (S1104/S1105 then S1106/S1107 or and S1106/S1107 thenS1104/S1105) or at least partially in parallel. So long as an order forcarrying any of the steps of any method discussed herein is technicallyfeasible, it is explicitly encompassed within the present disclosure.

As used herein, transmitting information or a message to an element mayinvolve sending one or more messages to the element and may involvesending part of the information separately from the rest of theinformation. The number of “messages” involved may also vary dependingon the layer or granularity considered. For example transmitting amessage may involve using several resource elements in an LTEenvironment such that several signals at a lower layer correspond to asingle message at a higher layer. Also, transmissions from one terminalto another may relate to the transmission of any one or more of userdata, discovery information, control signalling and any other type ofinformation to be transmitted.

Also, whenever an aspect is disclosed in respect of an apparatus orsystem, the teachings are also disclosed for the corresponding method.Likewise, whenever an aspect is disclosed in respect of a method, theteachings are also disclosed for any suitable corresponding apparatus orsystem. Additionally, it is also hereby explicitly disclosed that forany teachings relating to a method or a system where it has not beenclearly specified which element or elements are configured to carry outa function or a step, any suitable element or elements that can carryout the function can be configured to carry out this function or step.For example any one or more of a mobile terminal (e.g. a D2D terminal),a RSU (e.g. a terminal-to-terminal relay node), a base station or anyother mobile node may be configured accordingly if appropriate, so longas it is technically feasible and not explicitly excluded.

Whenever the expressions “greater than” or “smaller than” or equivalentare used herein, it is intended that they discloses both alternatives“and equal to” and “and not equal to” unless one alternative isexpressly excluded.

It is noteworthy that even though the present disclosure has beendiscussed in the context of LTE and/or D2D, its teachings are applicableto but not limited to LTE or to other 3GPP standards. In particular,even though the terminology used herein is generally the same or similarto that of the LTE standards, the teachings are not limited to thepresent version of LTE and could apply equally to any appropriatearrangement not based on LTE and/or compliant with any other futureversion of an LTE or 3GPP or other standard (e.g. the 5G standards).

According to the present disclosure, there are provided methods andapparatuses for activating a vehicular-capable terminal to connect to abase station and/or road side unit. Accordingly a vehicular-capableterminal which would otherwise be in idle mode can then participate invehicular communications, if appropriate.

Further particular and preferred aspects of the present invention areset out in the accompanying independent and dependent claims. It will beappreciated that features of the dependent claims may be combined withfeatures of the independent claims in combinations other than thoseexplicitly set out in the claims.

Thus, the foregoing discussion discloses and describes merely exemplaryembodiments of the present invention. As will be understood by thoseskilled in the art, the present invention may be embodied in otherspecific forms without departing from the spirit or essentialcharacteristics thereof. Accordingly, the disclosure of the presentinvention is intended to be illustrative, but not limiting of the scopeof the invention, as well as other claims. The disclosure, including anyreadily discernible variants of the teachings herein, define, in part,the scope of the foregoing claim terminology such that no inventivesubject matter is dedicated to the public.

Respective features of the present disclosure are defined by thefollowing numbered clauses:

Clause 1. A method of activating a vehicular-capable terminal in amobile telecommunications system, the mobile telecommunications systemcomprising a plurality of base stations operable to communicate with thevehicular-capable terminal and wherein at least one base station of theplurality of base stations is configured to operate as a road side unitand wherein the method comprises:

the vehicular-capable terminal receiving a list of one or more basestations selected from the plurality of base stations;

upon detection that the vehicular-capable terminal is within range of afirst base station, the vehicular-capable terminal determining whetherto activate, based on the list of base stations, a connection with thefirst base station; and

upon determining to activate a connection with the first base station,the vehicular-capable terminal activating the connection with the firstbase station.

Clause 2. The method of clause 1 wherein determining whether to activatea connection with the first base station comprises identifying that thefirst base station is not on the list of one or more base stations.

Clause 3. The method of clause 1 wherein determining whether to activatea connection with the first base station comprises identifying that thefirst base station is on the list of one or more base stations, whereinthe one or more base stations are further selected from the at least onebase station.

Clause 4. The method of any preceding clause wherein, upon activation ofthe connection with the first base station, the vehicular-capableterminal exchanging vehicular related data with the first base station.

Clause 5. The method of any preceding clause wherein thevehicular-capable terminal is a vulnerable road user (VRU) terminal.

Clause 6. The method of any preceding clause wherein:

the vehicular-capable terminal activating a connection with the basestation comprises the vehicular-capable terminal not activating aconnection with a core network portion of the mobile telecommunicationssystem.

Clause 7. The method of clause 4 further comprising, upon activation ofthe connection with the first base station, the vehicular-capableterminal exchanging vehicular related data with the first base stationwhile the terminal is not connected to the core network portion of themobile telecommunications system.

Clause 8. The method of any preceding clause comprising the terminal,upon activation of the connection with the base station, not activatinga connection with an anchor element of a core network portion of themobile telecommunications system wherein, optionally, the anchor elementis a mobility manager entity (MME).

Clause 9. The method of any preceding clause wherein, upon detectionthat the vehicular-capable terminal is no longer within range of thefirst base station, the vehicular-capable terminal de-activating theconnection to the first base station and the vehicular-capable terminalswitching to an idle connection mode wherein, optionally, the idleconnection mode is an idle Radio Resources Control (RRC) mode.

Clause 10. The method of any preceding clause wherein thevehicular-capable terminal activating a connection with the first basestation comprises the vehicular-capable terminal switching to aconnected mode wherein, optionally, the connected mode is a connectedRadio Resources Control (RRC) mode.

Clause 11. The method according to any preceding clause wherein themethod further comprises the vehicle receiving the list of road sideunits from one of the plurality of base stations.

Clause 12. The method of any preceding clause wherein, upon activatingthe connection with the first base station, the first base stationtransmitting an updated list of one or more base stations.

Clause 13. The method of any preceding clause wherein the list of basestations is comprised in a tracking area list communicated by the mobiletelecommunications system to the vehicular-capable terminal.

Clause 14. A mobile telecommunications system for activating avehicular-capable terminal, the mobile telecommunications systemcomprising:

a vehicular-capable terminal, and

a plurality of base stations operable to communicate with thevehicular-capable terminal and wherein at least one base station of theplurality of base stations is configured to operate as a road side unitwherein the vehicular-capable terminal is configured to receive a listof one or more base stations selected from the plurality of basestations;

the vehicular-capable terminal is configured, upon detection that thevehicular-capable terminal is within range of a first base station, todetermine based on the list of base stations whether to activate aconnection with the first base station; and

the vehicular-capable terminal is configured, upon determining toactivate a connection with the first base station, to activate theconnection with the first base station.

15. A mobile telecommunications system for activating avehicular-capable terminal, the mobile telecommunications systemcomprising:

a vehicular-capable terminal, and

a plurality of base stations operable to communicate with thevehicular-capable terminal and wherein at least one base station of theplurality of base stations is configured to operate as a road side unitwherein the vehicular-capable terminal and the plurality of basestations are configured to carry out together the method of any ofclauses 1 to 13.

Clause 16. A vehicular-capable terminal for use in a mobiletelecommunications system, the mobile telecommunications systemcomprising a plurality of base stations operable to communicate with thevehicular-capable terminal and wherein at least one base station of theplurality of base stations is configured to operate as a road side unit,the vehicular-capable terminal comprising a transmitter, a receiver anda controller, wherein the controller is configured to:

receive, via the receiver, a list of one or more base stations selectedfrom the plurality of base stations;

upon detection that the vehicular-capable terminal is within range of afirst base station, determine based on the list of base stations whetherto activate a connection with the first base station; and

upon determining to activate a connection with the first base station,activate the connection with the first base station.

Clause 17. A vehicular-capable terminal for use in a mobiletelecommunications system, the vehicular-capable terminal comprising atransmitter, a receiver and a controller, wherein the transmitter,receiver and controller together are configured to operate as thevehicular-capable terminal of the mobile telecommunications system ofclause 14 or 15.

Clause 18. Circuitry for a vehicular-capable terminal for use in amobile telecommunications system, the mobile telecommunications systemcomprising a plurality of base stations operable to communicate with thevehicular-capable terminal and wherein at least one base station of theplurality of base stations is configured to operate as a road side unit,wherein the circuitry comprises a controller element and a transceiverelement configured to operate together to:

receive a list of one or more base stations selected from the pluralityof base stations;

upon detection that the vehicular-capable terminal is within range of afirst base station, determine based on the list of base stations whetherto activate a connection with the first base station; and

upon determining to activate a connection with the first base station,activate the connection with the first base station.

Clause 19. A base station for use in a mobile telecommunications system,the mobile telecommunications system comprising a plurality of basestations operable to communicate with the vehicular-capable terminal anda vehicular-capable terminal, wherein the base station is one of theplurality of base stations and is configured to operate as a road sideunit, the base station comprising a transmitter, a receiver and acontroller, wherein the controller is configured to:

transmit, via the transmitter, a list of one or more base stationsselected from the plurality of base stations to the vehicular-capableterminal, wherein the list is for use by the vehicular-capable terminalto determine based on the list of base stations whether to activate aconnection with a first base station of the plurality of base stations,upon detection that the vehicular-capable terminal is within range of afirst base station.

Clause 20. Circuitry for a base station for use in a mobiletelecommunications system, the mobile telecommunications systemcomprising a plurality of base stations operable to communicate with thevehicular-capable terminal and a vehicular-capable terminal wherein thebase station is one of the plurality of base stations and wherein thecircuitry comprises a controller element and a transceiver elementconfigured to operate together to:

transmit, via the transmitter, a list of one or more base stationsselected from the plurality of base stations to the vehicular-capableterminal, wherein the list is for use by the vehicular-capable terminalto determine based on the list of base stations whether to activate aconnection with a first base station of the plurality of base stations,upon detection that the vehicular-capable terminal is within range of afirst base station.

Clause 21. A method of activating a vehicular-capable terminal in amobile telecommunications system, the mobile telecommunications systemcomprising one or more base stations operable to communicate with thevehicular-capable terminal and one or more road side units operable tocommunicate with the vehicular-capable terminal, wherein the methodcomprises:

a first road side unit detecting the presence of the vehicular-capableterminal;

upon detection of the presence of the vehicular-capable terminal, thefirst road side unit notifying a first base station of the presence ofthe vehicular-capable terminal;

upon notification of the presence of the vehicular-capable terminal, thefirst base station instructing the vehicular-capable terminal to connectto the first base station by transmitting an activation message whereinthe activation message is addressed to a group of terminals comprisingthe vehicular-capable terminal; and

in response to the activation message, the vehicular-capable terminalactivating a connection with the first base station and/or with thefirst road side unit.

Clause 22. The method of clause 11 wherein the activation message is apaging message.

Clause 23. The method of clause 12 wherein the paging message isaddressed to all terminals within range of the first base station and/orall vehicular-capable terminals within range of the first base station.

Clause 24. The method of clause 12 or 13 wherein the paging message isaddressed all vehicular-capable terminals within range of the first basestation using at least one of:

a mobile subscriber identifier allocated for paging vehicular-capableterminals or to terminals associated with vulnerable road users; and

a network temporary identifier allocated for paging vehicular-capableterminals or to terminals associated with vulnerable road users.

Clause 25. The method of clause 11 wherein the activation message iscomprised in a system information message transmitted by the first basestation.

Clause 26. The method of one of clauses 11 to 15 further comprising, thefirst base station transmitting the activation message upon detectionthat the presence of the vehicular-capable terminal in the area of thefirst road side unit is associated with a safety risk for thevehicular-capable terminal.

Clause 27. The method of clause 16 further comprising estimating thesafety risk for the vehicular-capable terminal based on presenceinformation for one or more terminal other than the vehicular-capableterminal in the vicinity of the first road side unit.

Clause 28. The method of one of clauses 11 to 17 further comprising,upon activation of the connection with the first base station, thevehicular-capable terminal exchanging vehicular related data with thefirst road side unit.

Clause 29. The method of one of clauses 11 to 18, wherein activating aconnection with the first base station comprises activating a connectionwith the first base station and not with an element in a core networkportion of the mobile telecommunications system.

Clause 30. The method of clause 19 further comprising, upon activationof the connection with the first base station, the vehicular-capableterminal exchanging vehicular related data with the first road side unitwhile the terminal is not connected to an element in a core networkportion of the mobile telecommunications system

Clause 31. The method of one of clauses 21 to 30 wherein notifying afirst base station of the presence of the vehicular-capable terminalcomprises the first road side unit sending a notification message to thefirst base station, wherein the notification message does not include anindividual identifier for the vehicular-capable terminal.

Clause 32. The method of one of clauses 21 to 31 wherein thevehicular-capable terminal is a vulnerable road user (VRU) terminal.

Clause 33. The method of any of clauses 11 to 21 wherein the first basestation is configured to operate as a road side unit and wherein thefirst base station is the first road side unit.

Clause 34. The method of one of clauses 21 to 33 wherein the connectionwith the first base station is a Radio Resources Control (RRC)connection.

Clause 35. A mobile telecommunications system, the mobiletelecommunications system comprising:

a vehicular-capable terminal,

one or more base stations operable to communicate with thevehicular-capable terminal, and

one or more road side units operable to communicate with thevehicular-capable terminal,

wherein:

a first road side unit of the one or more road side units is configuredto detect the presence of the vehicular-capable terminal;

the first road side unit is configured to, upon detection of thepresence of the vehicular-capable terminal, notify a first base stationof the one or more base stations of the presence of thevehicular-capable terminal;

the first base station is configured to, upon notification of thepresence of the vehicular-capable terminal, instruct thevehicular-capable terminal to connect to the first base station bytransmitting an activation message wherein the activation message isaddressed to a group of terminals comprising the vehicular-capableterminal; and

the vehicular-capable terminal is configured to, in response to theactivation message, activate a connection with the first base stationand/or with the first road side unit.

Clause 36. A mobile telecommunications system, the mobiletelecommunications system comprising:

a vehicular-capable terminal,

one or more base stations operable to communicate with thevehicular-capable terminal, and

one or more road side units operable to communicate with thevehicular-capable terminal,

wherein the vehicular-capable terminal, the one or more base stationsand the one or more road side units are configured to carry out togetherthe method of any of clauses 21 to 34.

Clause 37. A vehicular-capable terminal for use in a mobiletelecommunications system, the mobile telecommunications systemcomprising one or more base stations operable to communicate with thevehicular-capable terminal and one or more road side units operable tocommunicate with the vehicular-capable terminal, the vehicular-capableterminal comprising a transmitter, a receiver and a controller, whereinthe controller is configured to:

advertise the presence of the vehicular-capable terminal to a first roadside unit of the one or more road side units;

receive, via the receiver, an activation message from a first basestation of the one or more base stations wherein the activation messageis addressed to a group of terminals comprising the vehicular-capableterminal and is for instruct the vehicular-capable terminal to connectto the first base station; and

responsive to the activation message, activate a connection with thefirst base station and/or with the first road side unit.

Clause 38. A vehicular-capable terminal for use in a mobiletelecommunications system, the vehicular-capable terminal comprising atransmitter, a receiver and a controller, wherein the transmitter,receiver and controller together are configured to operate as thevehicular-capable terminal of the mobile telecommunications system ofclause 35 or 36.

Clause 39. Circuitry for a vehicular-capable terminal for use in amobile telecommunications system, the mobile telecommunications systemcomprising one or more base stations operable to communicate with thevehicular-capable terminal and one or more road side units operable tocommunicate with the vehicular-capable terminal, wherein the circuitrycomprises a controller element and a transceiver element configured tooperate together to:

advertise the presence of the vehicular-capable terminal to a first roadside unit of the one or more road side units;

receive, via the receiver, an activation message from a first basestation of the one or more base stations wherein the activation messageis addressed to a group of terminals comprising the vehicular-capableterminal and is for instruct the vehicular-capable terminal to connectto the first base station; and

responsive to the activation message, activate a connection with thefirst base station and/or with the first road side unit.

Clause 40. A base station for use in a mobile telecommunications system,the mobile telecommunications system comprising one or more basestations operable to communicate with the vehicular-capable terminal andone or more road side units operable to communicate with thevehicular-capable terminal, wherein the base station is one of the oneor more of base stations, the base station comprising a transmitter, areceiver and a controller, wherein the controller is configured to:

receive a notification from a first road side unit of the one or moreroad side units, wherein the notification is for reporting a presence ofthe vehicular-capable terminal detected by the first road side unit; and

upon notification of the presence of the vehicular-capable terminal,instruct the vehicular-capable terminal to connect to the first basestation by transmitting an activation message wherein the activationmessage is addressed to a group of terminals comprising thevehicular-capable terminal.

Clause 41. A base station for use in a mobile telecommunications system,the base station comprising a transmitter, a receiver and a controllerwherein the transmitter, receiver and controller together are configuredto operate as the first base station of the mobile telecommunicationssystem of clause 35 or 36

Clause 42. Circuitry for a base station for use in a mobiletelecommunications system, the mobile telecommunications systemcomprising one or more base stations operable to communicate with thevehicular-capable terminal and one or more road side units operable tocommunicate with the vehicular-capable terminal wherein the base stationis one of the one or more of base stations and wherein the circuitrycomprises a controller element and a transceiver element configured tooperate together to:

receive a notification from a first road side unit of the one or moreroad side units, wherein the notification is for reporting a presence ofthe vehicular-capable terminal detected by the first road side unit; and

upon notification of the presence of the vehicular-capable terminal,instruct the vehicular-capable terminal to connect to the first basestation by transmitting an activation message wherein the activationmessage is addressed to a group of terminals comprising thevehicular-capable terminal.

Clause 43. A road side unit for use in a mobile telecommunicationssystem, the mobile telecommunications system comprising avehicular-capable terminal, one or more base stations operable tocommunicate with the vehicular-capable terminal and one or more roadside units operable to communicate with the vehicular-capable terminal,wherein the road side unit is one of the one or more road side units andcomprises a transmitter, a receiver and a controller, wherein thecontroller is configured to:

detect the presence of the vehicular-capable terminal; and

upon detection of the presence of the vehicular-capable terminal, notifya first base station of the one or more base stations of the presence ofthe vehicular-capable terminal for the first base station to instructthe vehicular-capable terminal to connect to the first base station bytransmitting an activation message, the activation message beingaddressed to a group of terminals comprising the vehicular-capableterminal.

Clause 44. A road side unit for use in a mobile telecommunicationssystem, the road side unit comprising a transmitter, a receiver and acontroller, wherein the transmitter, receiver and controller togetherare configured to operate as the first road side unit of the mobiletelecommunications system of clause 35 or 36.

Clause 45. Circuitry for a road side unit for use in a mobiletelecommunications system, the mobile telecommunications systemcomprising a vehicular-capable terminal, one or more base stationsoperable to communicate with the vehicular-capable terminal and one ormore road side units operable to communicate with the vehicular-capableterminal, the road side unit being one of the one or more road sideunits, wherein the circuitry comprises a controller element and atransceiver element configured to operate together to:

detect the presence of the vehicular-capable terminal; and

upon detection of the presence of the vehicular-capable terminal, notifya first base station of the one or more base stations of the presence ofthe vehicular-capable terminal for the first base station to instructthe vehicular-capable terminal to connect to the first base station bytransmitting an activation message, the activation message beingaddressed to a group of terminals comprising the vehicular-capableterminal.

Clause 46. Computer software which, when executed by a computer, causesthe computer to perform the method of any one of clauses 1 to 13 and 21to 34.

Clause 47. A storage medium which stores computer software according toclause 46.

Clause 48. A method of activating a vehicular-capable terminal, a mobiletelecommunications system, a vehicular-capable terminal, circuitry for avehicular-capable terminal, a base station, circuitry for a basestation, a method of activating a vehicular-capable terminal, a roadside unit, circuitry for a road side unit, computer software and astorage medium substantially as hereinbefore described with reference tothe accompanying drawings.

Clause 49. Any preceding clause wherein the terminal, the road sideunit, the base station and the mobile telecommunications system areoperable to communicate at least one of: a 3GPP communication protocol,an LTE communication protocol, a 4G communication protocol and a 5Gcommunication protocol

REFERENCES

-   [1] Holma H. and Toskala A., “LTE for UMTS OFDMA and SC-FDMA based    radio access”, John Wiley and Sons, 2009-   [2] 3GPP TS 23.003, “Technical Specification Group Core Network and    Terminals; Numbering, addressing and identification”, Release 13, v    13.3.0, September 2015-   [3] U.S. Pat. No. 8,537,751 B2, “Minimizing tracking area updates in    heterogeneous radio access network”, 2013 Sep. 17-   [4] US 20150002311 A1, “Active beacon for vulnerable road users”,    2015 Jan. 1-   [5] DE 102012211172 A1, “Method for protecting vulnerable road user    from possible collision with vehicle, involves receiving or    generating hint to possible collision of vulnerable road user with    vehicle and sending command to device”, 2014 Apr. 3-   [6] US 2011090093 A1, “Vehicle to Entity Communication”, 2011 Apr.    21

The invention claimed is:
 1. Circuitry for a vehicular-capable terminalfor use in a mobile telecommunications system, wherein the circuitrycomprises a controller element and a transceiver element configured tooperate together to: receive a list of two or more base stations,wherein the list includes: a first list of one or more base stationsthat the vehicular-capable terminal is authorized to connect, and asecond list of one or more base stations that the vehicular-capableterminal is not authorized to connect; while the vehicular-capableterminal is in an idle mode, receive a notification that thevehicular-capable terminal has been detected within range of a firstbase station, based on the notification, determine based on the firstlist and the second list whether to activate a connection with the firstbase station; and upon determining to activate a connection with thefirst base station, exit the idle mode and activate the connection withthe first base station, wherein, upon exiting the idle mode andactivating the connection with the first base station, the circuitry isconfigured not to activate a connection with a core network portion ofthe mobile telecommunications system that controls the first basestation.
 2. The circuitry of claim 1, wherein determining whether toactivate a connection with the first base station comprises identifyingthat the first base station is not on the second list.
 3. The circuitryof claim 1, wherein the circuitry is configured to activate theconnection with the first base station only upon confirming that thefirst base station is on the first list and is not on the second list.4. The circuitry of claim 1, wherein, upon activation of the connectionwith the first base station, the circuitry is configured to exchangevehicular related data with the first base station.
 5. The circuitry ofclaim 1, wherein the vehicular-capable terminal is a vulnerable roaduser (VRU) terminal.
 6. The circuitry of claim 1, wherein, uponactivation of the connection with the first base station, the circuitryis configured to exchange vehicular related data with the first basestation while the vehicular-capable terminal is not connected to thecore network portion of the mobile telecommunications system thatcontrols the first base station.
 7. The circuitry of claim 1, whereinupon activation of the connection with the base station, thevehicular-capable terminal is configured not to activate a connectionwith an anchor element of a core network portion of the mobiletelecommunications system that controls the first base station, and theanchor element is a mobility manager entity (MME).
 8. The circuitry ofclaim 1, wherein, upon detection that the vehicular-capable terminal isno longer within range of the first base station, the circuitry isconfigured to: de-activate the connection to the first base station, andswitch the vehicular-capable terminal back to the idle mode, and theidle mode is an idle Radio Resources Control (RRC) mode.
 9. Thecircuitry of claim 1, wherein the circuitry is configured to activatethe connection with the first base station by switching from the idlemode to a connected mode, the idle mode being an idle Radio ResourcesControl (RRC) mode, and the connected mode being a connected RRC mode.10. The circuitry of claim 1, wherein, upon activating the connectionwith the first base station, the circuitry is configured to receive alist of road side units from the mobile telecommunications system. 11.The circuitry of claim 1, wherein, upon activating the connection withthe first base station, the first base station is configured to transmitan update to the list.
 12. The circuitry of claim 1, wherein uponactivation of the connection with the base station, the circuitry isconfigured to activate a connection with an anchor element of a corenetwork portion of the mobile telecommunications system, and the anchorelement is a mobility manager entity (MME).
 13. The circuitry of claim1, wherein the list of two or more base stations is comprised in atracking area list communicated by the mobile telecommunications systemto the vehicular-capable terminal.
 14. The circuitry of claim 1, whereinthe circuitry is configured to notify, while in the idle mode, apresence of the vehicular-capable terminal to a road side unitassociated with the first base station, in response to being notified ofthe presence of the vehicular-capable terminal, the road side unit isconfigured to report the presence of the vehicular-capable terminal to amaster base station via the first base station, and in response to thereported presence of the vehicular-capable terminal, the master basestation is configured to alert the vehicular-capable terminal to wake upfrom the idle mode and determine whether to activate the connection withthe first base station.
 15. The circuitry of claim 1, wherein thecircuitry is configured to determine whether the vehicular-capableterminal is within the range of the first base station.
 16. A methodperformed by circuitry of a vehicular-capable terminal for use in amobile telecommunications system, wherein the circuitry comprises acontroller element and a transceiver element, the method comprising:receiving a list of two or more base stations, wherein the listincludes: a first list of one or more base stations that thevehicular-capable terminal is authorized to connect, and a second listof one or more base stations that the vehicular-capable terminal is notauthorized to connect; while the vehicular-capable terminal is in anidle mode, receiving a notification that the vehicular-capable terminalhas been detected within range of a first base station, based on thenotification, determining based on the first list and the second listwhether to activate a connection with the first base station; and upondetermining to activate a connection with the first base station,exiting the idle mode and activating the connection with the first basestation, wherein the method further comprises, upon exiting the idlemode and activating the connection with the first base station, notactivating a connection with a core network portion of the mobiletelecommunications system that controls the first base station.
 17. Themethod of claim 16, wherein, upon activation of the connection with thefirst base station, the method further comprises exchanging vehicularrelated data with the first base station while the vehicular-capableterminal is not connected to the core network portion of the mobiletelecommunications system that controls the first base station.